/* DaVinci Learning — 站点样式：「纸上编辑部」 */
/* 设计决策（对照 design-lab/style-paper.html）：
   1. 奶油纸底 #faf7f0 + 藏青墨色正文 #1f2a3d，纸张与油墨的冷暖对比。
   2. 标题宋体系衬线（Songti SC / STSong / Georgia），正文无衬线系统栈，mono 系统栈。
   3. 唯一强调色砖红 #b5502a：关键词下划线、编号、标记符号，克制不铺色块。
   4. 区块不用卡片，全靠发丝线分节 + generous 留白；动效克制（淡入，无弹跳）。
   五区块五色编码已取消，编号徽章统一为砖红小号衬线数字 + mono 副题 + 发丝线。 */

:root {
  --paper: #faf7f0;
  --nav-bg: rgba(250, 247, 240, .92);
  --img-bg: #f3efe6;
  --rule-strong: rgba(31, 42, 61, .28);
  --rule-mid: rgba(31, 42, 61, .22);
  --ink-body: rgba(31, 42, 61, .85);
  --ink: #1f2a3d;
  --ink2: rgba(31, 42, 61, .78);
  --ink3: rgba(31, 42, 61, .68);
  --brick: #b5502a;
  --brick-deep: #96421f;
  --brick-tint: rgba(181, 80, 42, .07);
  --brick-rule: rgba(181, 80, 42, .45);
  --rule: rgba(31, 42, 61, .16);
  --rule-soft: rgba(31, 42, 61, .1);
  --sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  --serif: var(--sans);   /* 用户决定：全站统一默认正文字体，不再使用宋体衬线 */
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  --ok: #3d7a4e;   /* 测验对错反馈（仅语义反馈，非强调色） */
  --bad: #b03a2e;
  /* 区块五色相 + callout 教材色（蓝/绿/琥珀/绛紫，砖红为品牌主色） */
  --hue-blue: #3a6ea5;  --hue-blue-tint: rgba(58, 110, 165, .08);  --hue-blue-rule: rgba(58, 110, 165, .45);
  --hue-green: #3f7d5a; --hue-green-tint: rgba(63, 125, 90, .08);  --hue-green-rule: rgba(63, 125, 90, .45);
  --hue-amber: #b07d2b; --hue-amber-tint: rgba(176, 125, 43, .10); --hue-amber-rule: rgba(176, 125, 43, .45);
  --hue-plum: #a03d63;  --hue-plum-tint: rgba(160, 61, 99, .08);   --hue-plum-rule: rgba(160, 61, 99, .45);

  /* 语义 token 重映射：components.css 的 .btn 等自动落到纸上编辑部配色 */
  --background: var(--paper);
  --foreground: var(--ink);
  --card: #fffdf8;
  --border: var(--rule);
  --muted-foreground: var(--ink3);
  --link: var(--brick);
  --primary: var(--brick);
  --color-primary: var(--brick);
  --color-primary-hover: var(--brick-deep);
  --color-on-primary: #fffdf8;
  --color-primary-container: var(--brick-tint);
  --color-on-primary-container: var(--brick-deep);
  --accent: var(--brick);
  --accent-hover: var(--brick-deep);
  --accent-foreground: #fffdf8;
  --color-secondary-container: rgba(31, 42, 61, .06);
  --color-on-secondary-container: var(--ink2);
  --surface-dim: rgba(31, 42, 61, .05);
  --surface-container-low: rgba(31, 42, 61, .03);
  --popover: #fffdf8;
  --ring: var(--brick);
  --font-display: var(--serif);
  --font-heading: var(--serif);
  --font-body: var(--sans);
  --font-mono: var(--mono);
  --shadow-1: 0 1px 2px rgba(31, 42, 61, .05);
  --shadow-2: 0 2px 10px rgba(31, 42, 61, .07);
  --shadow-3: 0 6px 24px rgba(31, 42, 61, .09);
  --shadow-4: 0 10px 36px rgba(31, 42, 61, .12);
}

/* === 双语显隐 === */
html[data-lang="zh"] [lang-en] { display: none; }
html[data-lang="en"] [lang-zh] { display: none; }

/* === 基础排版 === */
* { box-sizing: border-box; }
html { background: var(--paper); }
/* 背景：纸色斜渐变基底（165°）+ 右上角暖金光晕（光源感）+ 粗颗粒纸纹（feTurbulence data-URI，兼作抗色带抖动） */
body { margin: 0; font-family: var(--sans); font-size: 16.5px; line-height: 1.8; color: var(--ink); -webkit-font-smoothing: antialiased;
  background:
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='180' height='180'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.7' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='180' height='180' filter='url(%23n)' opacity='0.045'/%3E%3C/svg%3E"),
    radial-gradient(ellipse 80% 50% at 85% -10%, rgba(184,137,90,.22), transparent 62%),
    linear-gradient(165deg, #fbf8f1 0%, #f4ecdb 55%, #ead7b6 100%);
  background-attachment: fixed; }

/* === 深色主题（变量整体翻转，结构/排版不动） === */
html[data-theme="dark"] {
  --paper: #161019;
  --nav-bg: rgba(22, 16, 25, .92);
  --img-bg: #231b2e;
  --rule-strong: rgba(236, 228, 212, .3);
  --rule-mid: rgba(236, 228, 212, .22);
  --ink-body: rgba(236, 228, 212, .85);
  --ink: #ece4d4;
  --ink2: rgba(236, 228, 212, .78);
  --ink3: rgba(236, 228, 212, .55);
  --brick: #d0704a;
  --brick-deep: #e0855f;
  --brick-tint: rgba(208, 112, 74, .13);
  --brick-rule: rgba(208, 112, 74, .5);
  --rule: rgba(236, 228, 212, .18);
  --rule-soft: rgba(236, 228, 212, .1);
  --ok: #6fae83;
  --bad: #d06a5a;
  --hue-blue: #7aa5d1;  --hue-blue-tint: rgba(122, 165, 209, .1);  --hue-blue-rule: rgba(122, 165, 209, .5);
  --hue-green: #7ab093; --hue-green-tint: rgba(122, 176, 147, .1); --hue-green-rule: rgba(122, 176, 147, .5);
  --hue-amber: #d9a955; --hue-amber-tint: rgba(217, 169, 85, .12); --hue-amber-rule: rgba(217, 169, 85, .5);
  --hue-plum: #cf7f9c;  --hue-plum-tint: rgba(207, 127, 156, .1);  --hue-plum-rule: rgba(207, 127, 156, .5);
  --card: #211a2b;
  --color-on-primary: #241a10;
  --accent-foreground: #241a10;
  --color-secondary-container: rgba(236, 228, 212, .08);
  --surface-dim: rgba(236, 228, 212, .06);
  --surface-container-low: rgba(236, 228, 212, .04);
  --popover: #211a2b;
  --shadow-1: 0 1px 2px rgba(0, 0, 0, .3);
  --shadow-2: 0 2px 10px rgba(0, 0, 0, .35);
  --shadow-3: 0 6px 24px rgba(0, 0, 0, .4);
  --shadow-4: 0 10px 36px rgba(0, 0, 0, .45);
}
/* 深色背景：黑紫斜渐变（165°）+ 右上角紫色光晕 + 粗颗粒噪点（频率更低、透明度更高，颗粒感明显） */
html[data-theme="dark"] body {
  background:
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='180' height='180'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.55' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='180' height='180' filter='url(%23n)' opacity='0.09'/%3E%3C/svg%3E"),
    radial-gradient(ellipse 80% 50% at 85% -10%, rgba(160, 115, 225, .18), transparent 62%),
    linear-gradient(165deg, #100c17 0%, #1c1329 55%, #2c1c40 100%);
  background-attachment: fixed;
}
::selection { background: rgba(181, 80, 42, .18); }
main { max-width: 800px; margin: 0 auto; padding: 0 48px 80px; }
main.main-wide { max-width: 1040px; }
main.book-wide { max-width: 1000px; }
h1, h2, h3, h4 { font-family: var(--serif); }
a { color: var(--brick); text-decoration: none; }
a:hover { text-decoration: underline; }
img, video { max-width: 100%; border-radius: 2px; }
video { display: block; background: #000; }
code { font-family: var(--mono); font-size: .88em; background: var(--color-secondary-container); border-radius: 3px; padding: 2px 6px; }
section[id] { scroll-margin-top: 84px; }

/* === 顶部迷你导航（发丝线下边条 + 衬线 logo） === */
.site-nav { position: sticky; top: 0; z-index: 100; display: flex; align-items: center; flex-wrap: wrap; gap: 8px 22px; min-height: 62px; padding: 0 48px; background: var(--nav-bg); backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px); border-bottom: 1px solid var(--rule); }
.nav-logo { display: flex; align-items: center; color: var(--ink); }
.logo-text { font-family: var(--serif); font-size: 17px; font-weight: 700; letter-spacing: 1px; }
.nav-logo:hover { text-decoration: none; }
.nav-logo:hover .logo-text { color: var(--brick); }
.site-nav nav { display: flex; flex-wrap: wrap; gap: 2px; }
.nav-tab { position: relative; display: inline-flex; align-items: center; padding: 6px 10px; color: var(--ink3); font-size: 14px; line-height: 1.4; transition: color .15s; }
.nav-tab:hover { color: var(--brick); text-decoration: none; }
.nav-tab.active { color: var(--brick); font-weight: 600; }
.nav-tab.active::after { content: ""; position: absolute; left: 10px; right: 10px; bottom: 0; height: 1px; background: var(--brick); }
.nav-tab.nav-ai { color: var(--brick); }
.nav-tools { margin-left: auto; position: relative; display: flex; align-items: center; gap: 10px; }
#search-box { width: 180px; padding: 7px 12px; border: 1px solid var(--rule-strong); border-radius: 2px; background: transparent; color: var(--ink); font-family: inherit; font-size: 13px; outline: none; transition: border-color .15s, box-shadow .15s; }
#search-box::placeholder { color: var(--ink3); }
#search-box:focus { border-color: var(--brick); box-shadow: 0 0 0 3px var(--brick-tint); }
/* 导航按钮（语言/深浅色/标尺）基础样式统一在文末「悬停微交互」块 */

/* 搜索结果下拉 */
#search-results { position: absolute; top: calc(100% + 8px); right: 0; z-index: 150; width: 320px; max-height: 60vh; overflow: auto; padding: 6px; background: var(--popover); border: 1px solid var(--rule); border-radius: 2px; box-shadow: var(--shadow-3); }
#search-results a { display: block; padding: 8px 12px; border-radius: 2px; color: var(--ink); font-size: 14px; }
#search-results a:hover { background: var(--brick-tint); text-decoration: none; }
#search-results p { margin: 6px; color: var(--ink3); font-size: 13px; }

/* === 阅读进度条（砖红单点） === */
#reading-progress { position: fixed; top: 0; left: 0; z-index: 200; width: 0; height: 2px; background: var(--brick); }

/* === 滚动渐入：克制的淡入，无弹跳 === */
.reveal { opacity: 0; transform: translateY(8px); transition: opacity .5s ease-out, transform .5s ease-out; }
.revealed { opacity: 1; transform: none; }

/* === 按钮（.btn 主体在 components.css，这里收敛为编辑部气质） === */
.btn { border-radius: 2px; font-weight: 600; }
.btn:hover { text-decoration: none; }

/* === 首页 Hero：衬线大标题 + 发丝线，取消色块 === */
.hero { padding: 56px 0 36px; border-bottom: 1px solid var(--rule); }
.hero .hero-eyebrow { margin: 0 0 14px; font-size: 12px; letter-spacing: 4px; color: var(--brick); }
.hero h1 { margin: 0 0 12px; font-size: 42px; font-weight: 700; letter-spacing: 2px; line-height: 1.2; }
.hero .hero-lead { margin: 0; max-width: 54ch; font-size: 16.5px; line-height: 1.75; color: var(--ink2); }

/* === 首页欢迎区：我是谁 / 这是什么 / 从哪开始（三栏，窄屏纵排） === */
.welcome { padding: 34px 0 30px; border-bottom: 1px solid var(--rule); }
.welcome-cols { display: grid; grid-template-columns: repeat(3, 1fr); gap: 34px; }
@media (max-width: 760px) { .welcome-cols { grid-template-columns: 1fr; gap: 22px; } }
.welcome-col h2 { display: flex; align-items: center; gap: 12px; margin: 0 0 10px;
  font-family: var(--mono); font-size: 11px; font-weight: 400; letter-spacing: 3px;
  text-transform: uppercase; color: var(--brick); }
.welcome-col h2::after { content: ""; flex: 1; height: 1px; background: var(--rule); }
.welcome-col p { margin: 0; font-size: 14.5px; line-height: 1.85; color: var(--ink2); }
.welcome-start a { color: var(--brick); text-decoration: underline; text-underline-offset: 3px; }
.welcome-start a:hover { background: var(--brick-tint); text-decoration: none; }

/* === 首页三条路：一行三个紧凑小卡（图标 + 标题 + 一句描述） === */
.door-row { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; padding: 20px 0 26px; border-bottom: 1px solid var(--rule); }
@media (max-width: 760px) { .door-row { grid-template-columns: 1fr; } }
.door-card { display: flex; align-items: center; gap: 14px; padding: 15px 18px;
  border: 1px solid var(--rule); border-radius: 8px; color: var(--ink);
  transition: border-color .15s, background .15s, transform .18s ease-out, box-shadow .18s ease-out; }
.door-card:hover { border-color: var(--brick); background: var(--brick-tint); text-decoration: none;
  transform: translateY(-2px); box-shadow: var(--shadow-1); }
.door-card:hover .axis-go { transform: translateX(4px); }
.door-body { display: flex; flex-direction: column; gap: 3px; min-width: 0; }
.door-title { font-family: var(--serif); font-size: 16.5px; font-weight: 700; letter-spacing: .5px; }
.door-desc { font-size: 12.5px; color: var(--ink3); }

/* === 图标 chip：圆角软底色方块 + 线条 SVG（--tint 可换色，color-mix 深浅色自适应） === */
.icon-chip { display: inline-flex; align-items: center; justify-content: center;
  width: 38px; height: 38px; flex-shrink: 0; border-radius: 9px;
  color: var(--tint, var(--brick));
  background: color-mix(in srgb, var(--tint, var(--brick)) 11%, transparent); }
.door-card .icon-chip { width: 42px; height: 42px; border-radius: 10px; }

/* === 双轴入口：克制的发丝线列表（取消撞色大色块） === */
.axis-entry { border-bottom: 1px solid var(--rule); }
.axis-row { display: flex; align-items: baseline; gap: 26px; padding: 28px 4px; border-top: 1px solid var(--rule-soft); color: var(--ink); transition: background .15s; }
.axis-row:hover { background: var(--brick-tint); text-decoration: none; }
.axis-num { font-family: var(--serif); font-size: 24px; font-weight: 700; color: var(--brick); line-height: 1; flex-shrink: 0; }
.axis-body { display: flex; flex-direction: column; gap: 4px; min-width: 0; }
.axis-title { font-family: var(--serif); font-size: 22px; font-weight: 700; letter-spacing: 1px; }
.axis-desc { font-size: 14px; color: var(--ink3); }
.axis-go { margin-left: auto; font-family: var(--sans); font-size: 20px; color: var(--brick); flex-shrink: 0; transition: transform .15s; }
.axis-row:hover .axis-go { transform: translateX(4px); }
/* 书架页筹备中占位卡：视觉降级（变淡 + 虚线），不可点 */
.axis-row.book-planned { border-top-style: dashed; opacity: .55; }
.axis-row.book-planned:hover { background: none; }

/* === 书架页：书封面卡 === */
.shelf-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(420px, 1fr)); gap: 24px; margin-top: 12px; }
@media (max-width: 560px) { .shelf-grid { grid-template-columns: 1fr; } }
.shelf-book { display: flex; gap: 22px; padding: 22px; color: var(--ink);
  border: 1px solid var(--rule); border-radius: 10px;
  transition: border-color .15s, transform .18s ease-out, box-shadow .18s ease-out; }
.shelf-book:hover { border-color: var(--brick-rule); transform: translateY(-3px);
  box-shadow: var(--shadow-2); text-decoration: none; }
.sb-cover { position: relative; flex-shrink: 0; width: 148px; min-height: 200px; overflow: hidden;
  display: flex; flex-direction: column; justify-content: flex-end; gap: 6px; padding: 16px 14px;
  border-radius: 3px 10px 10px 3px; color: #fdf6ee;
  background: linear-gradient(150deg, var(--cov1), var(--cov2));
  box-shadow: inset 5px 0 0 rgba(0,0,0,.22), inset 6px 0 3px rgba(0,0,0,.18), var(--shadow-1); }
.sb-mark { position: absolute; top: 6px; right: 4px; font-family: var(--serif);
  font-size: 64px; font-weight: 700; line-height: 1; color: rgba(255,255,255,.14);
  transform: rotate(-4deg); pointer-events: none; }
.sb-eyebrow { font-family: var(--mono); font-size: 9px; letter-spacing: 2px; opacity: .75; }
.sb-ctitle { font-family: var(--serif); font-size: 16.5px; font-weight: 700; line-height: 1.4; }
.sb-ctitle [lang-en] { font-size: 11.5px; font-weight: 400; opacity: .8; }
.sb-meta { display: flex; flex-direction: column; gap: 10px; min-width: 0; padding: 4px 0; }
.sb-name { font-family: var(--serif); font-size: 17px; font-weight: 700; color: var(--ink); line-height: 1.4; }
.sb-name [lang-en] { font-size: 12px; font-weight: 400; color: var(--ink3); }
.sb-desc { flex: 1; font-size: 13.5px; line-height: 1.7; color: var(--ink2); }
.sb-foot { display: flex; align-items: center; justify-content: space-between; }
.shelf-book.book-planned { opacity: .55; }
.shelf-book.book-planned:hover { transform: none; box-shadow: none; border-color: var(--rule); }
.shelf-book.book-planned .sb-cover { filter: saturate(.25); }

/* === 课列表路线图：S 弯路径 + 分层节点（重点课上车道，基础课下车道） === */
.rm-wrap { margin: 20px 0 8px; }
.rm-map { width: 100%; height: auto; display: block; }
.rm-path-bg { fill: none; stroke: var(--rule-strong); stroke-width: 2; opacity: .55; }
.rm-path-dots { fill: none; stroke: var(--brick); stroke-width: 2.5; opacity: .4;
  stroke-dasharray: 1 9; stroke-linecap: round; }
.rm-prog { fill: none; stroke: var(--brick); stroke-width: 3; stroke-linecap: round;
  stroke-dasharray: 0 100; }
.rm-flag path:first-child { stroke: var(--ink3); stroke-width: 2; fill: none; }
.rm-flag path:last-child { fill: var(--brick); }
.rm-ring { fill: var(--card); stroke: var(--ink3); stroke-width: 1.5;
  transform-box: fill-box; transform-origin: center; transition: transform .18s ease-out; }
.rm-progring { fill: none; stroke: var(--brick); stroke-width: 3; opacity: .9;
  stroke-dasharray: 0 245; transition: stroke-dasharray .3s; }
.rm-done .rm-progring { stroke: var(--ok); }
.rm-done .rm-ring { stroke: var(--ok); }
.rm-pulse { fill: none; stroke: var(--brick); stroke-width: 2; opacity: 0;
  transform-box: fill-box; transform-origin: center; }
.rm-next .rm-pulse { animation: rm-pulse 1.8s ease-out infinite; }
@keyframes rm-pulse { 0% { opacity: .55; transform: scale(1); } 100% { opacity: 0; transform: scale(1.55); } }
@media (prefers-reduced-motion: reduce) { .rm-next .rm-pulse { animation: none; } }
.rm-num { font-family: var(--serif); font-size: 26px; font-weight: 700; fill: var(--ink); }
.rm-label { font-size: 21px; font-weight: 600; fill: var(--ink2); }
.rm-k .rm-ring { fill: var(--brick); stroke: var(--brick); }
.rm-k .rm-num { fill: #fdf6ee; }
.rm-f .rm-label { fill: var(--ink3); font-weight: 400; }
.rm-star .rm-ring { fill: var(--card); stroke: var(--brick); stroke-width: 2; }
.rm-star-glyph { font-size: 34px; fill: var(--brick); }
.rm-node:hover .rm-ring { transform: scale(1.14); }
.rm-node:hover .rm-label { fill: var(--brick); }
.rm-legend { display: flex; align-items: center; gap: 8px; margin: 4px 0 0;
  font-family: var(--mono); font-size: 11.5px; letter-spacing: 1px; color: var(--ink3); }
.rm-legend .rm-dot { width: 10px; height: 10px; border-radius: 50%; display: inline-block; }
.rm-legend .rm-k { background: var(--brick); }
.rm-legend .rm-f { border: 1.5px solid var(--ink3); }
.rm-legend .rm-ringdot { border: 2px solid var(--ok); }
.rm-legend span[lang-zh], .rm-legend span[lang-en] { margin-right: 14px; }
.rm-quiz { margin-top: 8px; border-top: 1px solid var(--rule); }
.rm-flat { display: none; }
@media (max-width: 860px) {
  .rm-map, .rm-legend { display: none; }
  .rm-flat { display: block; }
}

/* === 区域标题：衬线标题 + mono 小字副题 + 发丝线分节 === */
#topics { margin-top: 52px; border-top: 1px solid var(--rule); padding-top: 32px; }
.sec-head { margin: 0 0 24px; }
.sec-head h2 { display: flex; align-items: baseline; gap: 18px; margin: 0; font-size: 28px; font-weight: 700; letter-spacing: 2px; }
.sec-head h2::before { content: ""; width: 22px; height: 1px; background: var(--brick); align-self: center; }
.sec-sub { margin: 8px 0 0; font-family: var(--mono); font-size: 11px; letter-spacing: 3px; text-transform: uppercase; color: var(--ink3); }

/* 路线图「开工准备」（GS）节点字号收窄 */
.rm-num-sm { font-size: 19px; }

/* === 首页领域卡：发丝线行 === */
.topic-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 14px; }
.topic-card { display: flex; flex-direction: row; align-items: center; justify-content: space-between; gap: 14px; padding: 14px 18px; background: transparent; border: 1px solid var(--rule); border-radius: 2px; color: var(--ink); transition: border-color .15s, background .15s; }
.topic-card:hover { border-color: var(--brick); background: var(--brick-tint); text-decoration: none; }
.topic-body { display: flex; flex-direction: column; gap: 2px; min-width: 0; }
.topic-title { font-family: var(--serif); font-size: 18px; font-weight: 700; letter-spacing: 1px; color: var(--ink); }
.topic-card:hover .topic-title { color: var(--brick); }
.topic-count { font-family: var(--mono); font-size: 12px; color: var(--ink3); }

/* === 单元页 / 领域页 / 诊断页 Hero：编辑部级 === */
.page-hero { margin-bottom: 48px; padding: 64px 0 44px; border-bottom: 1px solid var(--rule); }
.page-hero .hero-eyebrow { margin: 0 0 14px; font-family: var(--mono); font-size: 12px; letter-spacing: 3px; text-transform: uppercase; color: var(--brick); }
.page-hero h1 { margin: 0 0 14px; font-size: 42px; font-weight: 700; letter-spacing: 2px; line-height: 1.25; }
.page-hero .intro { margin: 0 0 18px; max-width: 62ch; color: var(--ink2); font-size: 18px; line-height: 1.85; }
.page-hero .tag-row { margin: 0; }

/* === 卡片清单：发丝线行 + 衬线编号 === */
.card-list { list-style: none; counter-reset: topo; margin: 0; padding: 0; border-bottom: 1px solid var(--rule); }
.card-item { counter-increment: topo; display: flex; align-items: baseline; flex-wrap: wrap; gap: 8px 18px; padding: 18px 4px; border-top: 1px solid var(--rule-soft); transition: background .15s; }
.card-item::before { content: counter(topo, decimal-leading-zero); font-family: var(--serif); font-size: 20px; font-weight: 700; color: var(--brick); line-height: 1.4; flex-shrink: 0; }
.card-item:hover { background: var(--brick-tint); }
.card-item > a { flex: 1; min-width: 200px; font-family: var(--serif); font-size: 18px; font-weight: 700; letter-spacing: .5px; color: var(--ink); }
.card-item > a:hover { color: var(--brick); text-decoration: none; }

/* 目录页：多任务卡在卡名下挂任务链接列表（紧凑版） */
.card-tasks { flex-basis: 100%; margin-top: 8px; padding-left: 34px; }
.card-tasks .task-link { padding: 8px 4px; }
.card-tasks .task-t { font-size: 15px; }
.card-tasks .task-no { font-size: 12px; }
.unit-group { border-top: 1px solid var(--rule); padding: 8px 0 20px; }
.unit-group > summary { cursor: pointer; padding: 18px 4px 6px; font-family: var(--serif); font-size: 20px; font-weight: 700; letter-spacing: 1px; list-style: none; }
.unit-group > summary::-webkit-details-marker { display: none; }
.unit-group > summary:hover { color: var(--brick); }
.unit-group .card-list { margin-top: 10px; border-bottom: none; }
.empty-note { padding: 40px 0; text-align: center; color: var(--ink3); font-family: var(--serif); letter-spacing: 1px; }

/* === 标签：mono 小字 + 发丝描边，砖红仅用于强调 === */
.tag { display: inline-flex; align-items: center; gap: 4px; padding: 3px 9px; font-family: var(--mono); font-size: 11px; letter-spacing: 1px; line-height: 1.5; border: 1px solid var(--rule); border-radius: 2px; background: transparent; color: var(--ink2); white-space: nowrap; }
.tag.difficulty { color: var(--brick); border-color: var(--brick-rule); }
.tag.week-solid { color: var(--brick); border-color: var(--brick-rule); }
.tag.accent-solid { color: var(--brick); border-color: var(--brick-rule); }
a.tag { color: var(--brick); }
a.tag:hover { border-color: var(--brick); background: var(--brick-tint); text-decoration: none; }
.tag-row { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; margin: 12px 0; }

/* === 卡片页 Hero：style-paper 标签行风格（eyebrow + 衬线题 + 发丝线 meta） === */
.card-page > [lang-zh], .card-page > [lang-en] { display: block; }
.card-hero { padding: 64px 0 0; }
.breadcrumb { margin-bottom: 20px; font-family: var(--mono); font-size: 12px; letter-spacing: 1px; color: var(--ink3); }
.breadcrumb a { color: var(--ink3); }
.breadcrumb a:hover { color: var(--brick); }
.card-hero h1 { margin: 0 0 28px; font-size: 46px; font-weight: 700; letter-spacing: 2px; line-height: 1.2; }
.card-hero .meta { display: flex; flex-wrap: wrap; gap: 12px 36px; padding: 15px 0; border-top: 1px solid var(--rule-mid); border-bottom: 1px solid var(--rule-mid); font-size: 13.5px; color: var(--ink2); }
.card-hero .meta b { font-family: var(--serif); color: var(--brick); font-weight: 700; margin-right: 8px; }
.prereq-bar { margin: 0; padding: 14px 0; border-bottom: 1px dashed var(--rule); font-size: 13px; color: var(--ink3); }
.prereq-bar .tag { margin-right: 6px; }

/* === 五区块：发丝线分节 + 五色相编号（蓝/砖红/绿/琥珀/绛紫）+ mono 副题 === */
.card-page section.sec-block { border-top: 1px solid var(--rule); padding: 56px 0; font-size: 16.5px; line-height: 1.85; color: var(--ink); }
.card-page section h2 { display: flex; align-items: baseline; gap: 18px; margin: 0 0 32px; }
.sec-num { font-family: var(--sans); font-size: 30px; font-weight: 800; line-height: 1; color: var(--brick); }
.sec-title { font-family: var(--sans); font-size: 26px; font-weight: 700; letter-spacing: 2px; color: var(--ink); }
.sec-sub { margin-left: auto; font-family: var(--mono); font-size: 11px; letter-spacing: 3px; text-transform: uppercase; color: var(--ink3); }
.sec-blue  .sec-num { color: var(--hue-blue); }
.sec-brick .sec-num { color: var(--brick); }
.sec-green .sec-num { color: var(--hue-green); }
.sec-amber .sec-num { color: var(--hue-amber); }
.sec-plum  .sec-num { color: var(--hue-plum); }

/* 正文排版：strong=砖红关键词下划线，em=衬线斜体（单点强调，不引新色） */
.card-page section > p { margin: 0 0 20px; }
.card-page section > p:last-child { margin-bottom: 0; }
.card-page section strong { font-weight: 600; color: var(--brick); border-bottom: 2px solid rgba(181, 80, 42, .35); padding-bottom: 1px; }
.card-page section em { font-family: var(--sans); }
.fc-front strong, .fc-front em { color: inherit; border-bottom: none; font-family: inherit; }

/* 列表：「—」砖红起笔 / Georgia 编号 + 发丝线项距 */
.card-page section > ul, .card-page section > ol:not(.blk-steps) { list-style: none; margin: 0 0 20px; padding: 0; }
.card-page section > ul:last-child, .card-page section > ol:not(.blk-steps):last-child { margin-bottom: 0; }
.card-page section > ul li, .card-page section > ol:not(.blk-steps) li { position: relative; padding: 14px 0 14px 30px; border-top: 1px solid var(--rule-soft); color: var(--ink2); }
.card-page section > ul li::before { content: "—"; position: absolute; left: 0; top: 14px; color: var(--brick); font-weight: 700; }
.card-page section > ol:not(.blk-steps) { counter-reset: item; }
.card-page section > ol:not(.blk-steps) li { counter-increment: item; }
.card-page section > ol:not(.blk-steps) li::before { content: counter(item); position: absolute; left: 0; top: 14px; font-family: var(--sans); font-size: 20px; font-weight: 700; color: var(--brick); line-height: 1.3; }

.card-page section h3 { margin: 36px 0 14px; font-size: 20px; font-weight: 700; letter-spacing: 1px; color: var(--ink); }
.wiki-deep { margin: 24px 0 0; }
.wiki-deep a { display: inline-flex; align-items: center; gap: 8px; padding: 10px 18px; border: 1px solid var(--brick-rule); border-radius: 2px; color: var(--brick); font-family: var(--mono); font-size: 13px; letter-spacing: 1px; transition: background .15s, border-color .15s; }
.wiki-deep a:hover { background: var(--brick-tint); border-color: var(--brick); text-decoration: none; }
blockquote { margin: 20px 0; padding: 14px 20px; border-left: 2px solid var(--rule); color: var(--ink3); }

/* === 内容块 === */
/* 小节标题：长文卡（入门/概述类）的内部分节 */
.bsub { margin: 34px 0 6px; font-family: var(--sans); font-size: 19px; font-weight: 700; letter-spacing: .5px; color: var(--ink); }
.bsub:first-child { margin-top: 0; }

/* 入门卡交互演示（book-demos.js 挂载） */
.bdemo { margin: 22px 0; padding: 22px 24px; background: var(--card); border: 1px solid var(--rule); border-radius: 2px; }
.demo-stage { position: relative; overflow: hidden; border-radius: 2px; background: #000; }
.demo-stage canvas { display: block; width: 100%; height: auto; }
.demo-ctl { display: flex; align-items: center; gap: 14px; margin-top: 14px; }
.demo-lab { font-family: var(--mono); font-size: 12px; letter-spacing: 1px; color: var(--ink3); white-space: nowrap; }
.demo-cap { margin: 10px 0 0; font-size: 13px; color: var(--ink3); }
.bdemo input[type="range"] { flex: 1; accent-color: var(--brick); }

/* color-temp：冷暖罩层 */
.ct-stage { aspect-ratio: 480 / 300; }
.ct-tint { position: absolute; inset: 0; opacity: 0; pointer-events: none; transition: opacity .12s linear; }
.ct-cool { background: linear-gradient(180deg, #2b4d7a 0%, #3a6a9e 60%, #1d3550 100%); mix-blend-mode: color; }
.ct-warm { background: linear-gradient(180deg, #e8963c 0%, #d96f32 60%, #8f3f1d 100%); mix-blend-mode: color; }
.ct-mood { position: absolute; left: 14px; bottom: 12px; padding: 4px 12px; background: rgba(0,0,0,.55); color: #f5f0e8; font-family: var(--mono); font-size: 12px; letter-spacing: 1px; border-radius: 2px; }
.ct-canvas { transition: filter .12s linear; }

/* vfx-layers：分层合成舞台 */
.vl-stage { aspect-ratio: 16 / 9; background: #101010; }
.vl-layer { position: absolute; inset: 0; transition: opacity .3s ease, transform .3s ease; }
.vl-layer.off { opacity: 0; transform: translateY(6px); pointer-events: none; }
.vl-sky { background: linear-gradient(180deg, #7fb2d9 0%, #cfe3ee 70%, #e8e3d3 100%); }
.vl-mount { background: linear-gradient(135deg, transparent 55%, #5c6355 55.5%), linear-gradient(45deg, transparent 62%, #43483d 62.5%); opacity: .9; }
.vl-mount::after { content: ""; position: absolute; right: 8%; top: 30%; width: 34%; height: 42%; background: #6b7263; clip-path: polygon(0 100%, 30% 20%, 55% 60%, 75% 8%, 100% 100%); }
.vl-temple { background: transparent; }
.vl-temple::before { content: ""; position: absolute; left: 12%; bottom: 8%; width: 26%; height: 34%; background: #8f5a35; clip-path: polygon(0 100%, 0 35%, 50% 0, 100% 35%, 100% 100%); }
.vl-temple::after { content: ""; position: absolute; left: 9%; bottom: 38%; width: 32%; height: 8%; background: #6d3a1f; clip-path: polygon(50% 0, 100% 100%, 0 100%); }
.vl-person::before { content: ""; position: absolute; left: 58%; bottom: 10%; width: 4.5%; height: 16%; background: #2a2620; border-radius: 40% 40% 0 0; }
.vl-person::after { content: ""; position: absolute; left: 58.8%; bottom: 24%; width: 3%; aspect-ratio: 1; background: #2a2620; border-radius: 50%; }
.vl-title { display: flex; align-items: flex-start; justify-content: flex-end; padding: 6% 8%; font-family: var(--sans); font-size: clamp(28px, 5vw, 52px); font-weight: 800; letter-spacing: 4px; color: rgba(245,240,232,.92); text-shadow: 0 2px 12px rgba(0,0,0,.4); }
.vl-chips { flex-wrap: wrap; }
.vl-chip { padding: 6px 14px; border: 1px solid var(--brick-rule); border-radius: 2px; background: transparent; color: var(--ink3); font-family: var(--mono); font-size: 12px; letter-spacing: 1px; cursor: pointer; transition: all .15s; }
.vl-chip.on { background: var(--brick-tint); border-color: var(--brick); color: var(--brick); }
.vl-chip:hover { border-color: var(--brick); }

/* 滚动显现（book-demos.js 加 .rv / .rv-in） */
.rv { opacity: 0; transform: translateY(10px); }
.rv.rv-in { opacity: 1; transform: none; transition: opacity .45s ease, transform .45s ease; }

/* 步骤条：Georgia 大号砖红编号 + 发丝线分步（取消圆圈与连接线） */
.blk-steps { list-style: none; counter-reset: step; margin: 20px 0; padding: 0; }
.blk-steps li { counter-increment: step; position: relative; padding: 22px 0 22px 50px; border-top: 1px solid var(--rule-soft); color: var(--ink2); }
.blk-steps li::before { content: counter(step); position: absolute; left: 0; top: 22px; font-family: var(--sans); font-size: 28px; font-weight: 700; color: var(--brick); line-height: 1.1; width: 30px; text-align: center; }
.blk-steps .step-img { display: block; max-width: 100%; margin-top: 12px; padding: 6px; background: var(--card); border: 1px solid var(--rule); border-radius: 2px; }

/* callout：教材式彩色盒（note=蓝 / tip=绿 / warning=琥珀 / pitfall=绛紫，默认砖红） */
.blk-callout { margin: 28px 0; padding: 18px 24px; border-left: 3px solid var(--brick); background: var(--brick-tint); }
.blk-callout .callout-title { margin: 0 0 8px; font-family: var(--sans); font-weight: 700; font-size: 14px; letter-spacing: 3px; color: var(--brick); }
.blk-callout p { color: var(--ink2); font-size: 15.5px; }
.blk-callout p:last-child { margin-bottom: 0; }
.blk-callout.note { border-left-color: var(--hue-blue); background: var(--hue-blue-tint); }
.blk-callout.note .callout-title { color: var(--hue-blue); }
.blk-callout.tip { border-left-color: var(--hue-green); background: var(--hue-green-tint); }
.blk-callout.tip .callout-title { color: var(--hue-green); }
.blk-callout.warning { border-left-color: var(--hue-amber); background: var(--hue-amber-tint); }
.blk-callout.warning .callout-title { color: var(--hue-amber); }
.blk-callout.pitfall { border-left-color: var(--hue-plum); background: var(--hue-plum-tint); }
.blk-callout.pitfall .callout-title { color: var(--hue-plum); }

/* 折叠面板：发丝线 + 衬线题 + 砖红 ＋ 号 */
.blk-accordion { margin: 0; border-bottom: 1px solid var(--rule); }
.blk-accordion summary { cursor: pointer; display: flex; justify-content: space-between; align-items: baseline; gap: 22px; padding: 22px 0; font-family: var(--serif); font-size: 18px; font-weight: 700; letter-spacing: .5px; list-style: none; }
.blk-accordion summary::-webkit-details-marker { display: none; }
.blk-accordion summary::after { content: "＋"; font-family: var(--sans); font-weight: 400; font-size: 20px; color: var(--brick); flex-shrink: 0; transition: transform .15s; }
.blk-accordion[open] summary::after { transform: rotate(45deg); }
.blk-accordion summary:hover { color: var(--brick); }
.blk-accordion > p, .blk-accordion > :last-child { max-width: 660px; }
.blk-accordion > p { margin: 0 0 24px; color: var(--ink2); }

/* 翻牌卡：墨底纸字正面 / 纸面背面，缓动无弹跳 */
.blk-flashcard { max-width: 420px; margin: 20px 0; perspective: 800px; cursor: pointer; }
.fc-inner { position: relative; min-height: 120px; transform-style: preserve-3d; transition: transform .5s ease; }
.blk-flashcard.flipped .fc-inner { transform: rotateY(180deg); }
.fc-front, .fc-back { position: absolute; inset: 0; display: flex; align-items: center; justify-content: center; overflow: auto; padding: 24px; border-radius: 2px; text-align: center; backface-visibility: hidden; box-shadow: var(--shadow-1); }
.fc-front { background: var(--ink); color: var(--paper); font-family: var(--serif); font-size: 20px; letter-spacing: 1px; }
.fc-back { background: var(--card); color: var(--ink2); border: 1px solid var(--rule); transform: rotateY(180deg); }

/* 前后对比（叠图 + clip-path + 滑杆） */
.blk-compare { position: relative; margin: 20px 0; }
.blk-compare .cmp-wrap, .blk-compare > img, .blk-compare .cmp-after { border-radius: 2px; }
.blk-compare > img.cmp-before { display: block; width: 100%; border: 1px solid var(--rule); }
.blk-compare .cmp-after { position: absolute; inset: 0; overflow: hidden; clip-path: inset(0 0 0 50%); }
.blk-compare .cmp-after img { display: block; width: 100%; height: 100%; object-fit: cover; }
.blk-compare input[type="range"] { width: 100%; margin: 10px 0 0; accent-color: var(--brick); }

/* 随堂快测与单元自测选项：发丝描边，hover 浅砖底 */
.blk-check { margin: 20px 0; padding: 20px 24px; background: var(--card); border: 1px solid var(--rule); border-radius: 2px; }
.blk-check .ck-q { margin-top: 0; font-weight: 600; }
.blk-check ul, .quiz-card ul { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 8px; }
.blk-check li, .quiz-card li { padding: 10px 16px; border: 1px solid var(--rule); border-radius: 2px; cursor: pointer; transition: background .15s, border-color .15s; }
.blk-check li:hover, .quiz-card li:hover { border-color: var(--brick); background: var(--brick-tint); }
.blk-check li.right, .quiz-card li.right { border-color: var(--ok); background: rgba(61, 122, 78, .08); color: var(--ok); font-weight: 600; }
.blk-check li.wrong, .quiz-card li.wrong { border-color: var(--bad); background: rgba(176, 58, 46, .07); color: var(--bad); }
.ck-explain { margin: 12px 0 0; padding: 8px 12px; background: var(--surface-dim); border-radius: 2px; font-size: 13px; color: var(--ink2); }

/* 图片画廊 */
.blk-gallery { display: grid; grid-template-columns: repeat(auto-fill, minmax(180px, 1fr)); gap: 12px; margin: 20px 0; }
.blk-gallery img { border: 1px solid var(--rule); }

/* === 单元自测题（quiz.js 渲染） === */
.unit-quiz { margin-top: 72px; padding-top: 44px; border-top: 1px solid var(--rule); }
.unit-quiz > h2 { margin: 0 0 24px; font-size: 26px; font-weight: 700; letter-spacing: 2px; }
.quiz-card { margin: 16px 0; padding: 20px 24px; background: var(--card); border: 1px solid var(--rule); border-radius: 2px; }
.quiz-progress { margin: 0 0 8px; font-family: var(--mono); font-size: 12px; letter-spacing: 1px; color: var(--ink3); }
.quiz-q { margin-top: 0; font-weight: 600; }
.quiz-explain { margin: 12px 0 0; padding: 8px 12px; background: var(--surface-dim); border-radius: 2px; font-size: 13px; color: var(--ink2); }
.quiz-result { margin: 16px 0; padding: 40px 24px; text-align: center; background: var(--card); border: 1px solid var(--rule); border-radius: 2px; font-size: 18px; }
.quiz-result p { margin: 8px 0 20px; font-family: var(--serif); font-size: 32px; font-weight: 700; color: var(--brick); }

/* === 诊断树（stuck.js 渲染） === */
#stuck-tree { padding-top: 8px; }
#stuck-tree > h2 { margin: 0 0 20px; font-size: 24px; font-weight: 700; letter-spacing: 1px; }
.stuck-crumb { margin-bottom: 12px; font-size: 13px; color: var(--ink3); }
.stuck-crumb .crumb { padding: 0; border: none; background: transparent; color: var(--brick); font-size: inherit; cursor: pointer; }
.stuck-crumb .crumb:hover { text-decoration: underline; }
.stuck-opts { display: flex; flex-direction: column; gap: 12px; margin: 20px 0; }
.stuck-opt { display: flex; align-items: center; justify-content: space-between; gap: 12px; width: 100%; padding: 16px 22px; text-align: left; font-family: var(--serif); font-size: 17px; font-weight: 700; letter-spacing: .5px; color: var(--ink); background: transparent; border: 1px solid var(--rule); border-radius: 2px; cursor: pointer; transition: background .15s, border-color .15s; }
.stuck-opt::after { content: "→"; font-family: var(--sans); font-weight: 400; color: var(--brick); transition: transform .15s; }
.stuck-opt:hover { border-color: var(--brick); background: var(--brick-tint); }
.stuck-opt:hover::after { transform: translateX(4px); }
.stuck-cards { display: flex; flex-direction: column; margin-top: 28px; border-bottom: 1px solid var(--rule); }
.stuck-cards h3 { margin: 0 0 10px; font-size: 18px; }
.stuck-cards .card-link { display: block; padding: 14px 4px; border-top: 1px solid var(--rule-soft); color: var(--ink); font-family: var(--serif); font-size: 17px; font-weight: 700; letter-spacing: .5px; transition: color .15s, background .15s; }
.stuck-cards .card-link:hover { color: var(--brick); background: var(--brick-tint); text-decoration: none; }

/* === Wiki 深度层：纸张上的长文 === */
.wiki-page h1 { margin: 0 0 24px; padding-bottom: 16px; border-bottom: 1px solid var(--rule); font-size: 40px; font-weight: 700; letter-spacing: 2px; }
.wiki-page h2 { margin: 36px 0 14px; font-size: 24px; letter-spacing: 1px; }
.wiki-page h3 { margin: 28px 0 12px; font-size: 19px; }
.wiki-page p { color: var(--ink2); }

/* === 页脚：发丝线 + 居中衬线小字 === */
footer { border-top: 1px solid var(--rule-mid); }
.foot-inner { max-width: 800px; margin: 0 auto; padding: 36px 24px 52px; text-align: center; font-family: var(--serif); font-size: 13px; letter-spacing: 1px; color: var(--ink3); }
.foot-brand { margin: 0 0 8px; font-size: 15px; font-weight: 700; color: var(--ink2); }
.foot-note { margin: 0; font-size: 12px; }

/* === 教材跟练 v3：一子目录一卡页 === */
.book-sec-page .breadcrumb { margin: 26px 0 6px; font-size: 13.5px; }
.book-sec-page .breadcrumb a { color: var(--ink3); }
.book-sec-page .breadcrumb a:hover { color: var(--brick); }
.bsc-title { font-size: 34px; margin: 4px 0 10px; }
.book-sec-page .tag-row { margin: 0 0 18px; }

.bsec { margin: 26px 0; }
.bsec-intro h2 { display: flex; align-items: baseline; gap: 12px; margin: 0 0 14px; font-size: 15px; letter-spacing: 3px; color: var(--brick); }
.bsec-intro h2 .sec-title { font-weight: 700; }
.bpara { max-width: 72ch; font-size: 16.5px; line-height: 1.95; color: var(--ink-body); margin: 0 0 15px; text-wrap: pretty; white-space: pre-line; }
.bpara.lead { font-size: 18px; line-height: 1.85; color: var(--ink); }

/* 长文入门卡排版：首段首字下沉 + 小节自动编号 + 更强节奏 */
.bsec-intro { counter-reset: bsub; }
.bsec-intro .bpara.lead::first-letter {
  float: left; margin: 6px 10px 0 0;
  font-family: var(--serif); font-size: 3.1em; font-weight: 700;
  line-height: .86; color: var(--brick);
}
.bsec-intro .bsub {
  display: flex; align-items: baseline; gap: 12px;
  margin: 44px 0 10px; padding-top: 26px;
  border-top: 1px solid var(--rule-soft);
  counter-increment: bsub;
}
.bsec-intro .bsub::before {
  content: counter(bsub, decimal-leading-zero);
  font-family: var(--mono); font-size: 12px; font-weight: 400;
  letter-spacing: 2px; color: var(--brick);
}
.bsec-intro .bsub:first-of-type { border-top: 0; padding-top: 0; }
/* 小节内首段略作强调，段落间距收紧、行内更松 */
.bsec-intro .bsub + .bpara { color: var(--ink2); }
@media (max-width: 640px) {
  .bsec-intro .bpara.lead::first-letter { font-size: 2.6em; margin-top: 4px; }
}
.bgroup { margin: 18px 0; }
.bgroup + .bgroup { margin-top: 26px; padding-top: 22px; border-top: 1px solid var(--rule-soft); }

/* 「标签: 值」短条目（def） */
.bpara.def { display: flex; gap: 10px; align-items: baseline; flex-wrap: wrap; }
.bpara.def .def-k { font-family: var(--mono); font-size: 12.5px; letter-spacing: .5px; color: var(--brick-deep); background: var(--brick-tint); border: 1px solid var(--brick-rule); border-radius: 2px; padding: 1px 8px; white-space: nowrap; }
.bpara.def .def-k::after { content: none; }

/* 术语高亮 chips（教材页内） */
.book-sec-page code { font-family: var(--mono); font-size: .86em; background: var(--color-secondary-container); border: 1px solid var(--rule-soft); border-radius: 3px; padding: 1px 6px; white-space: nowrap; }
.book-sec-page kbd { font-family: var(--mono); font-size: .82em; color: var(--brick-deep); background: var(--card); border: 1px solid var(--brick-rule); border-bottom-width: 2px; border-radius: 3px; padding: 0 6px; white-space: nowrap; }
/* 步骤 = 纸面卡片 + 实心砖红号徽（要做的动作，页面上最重）；
   步骤间的解释段落 = 缩进 + 左侧发丝轨 + 更小更淡（从属说明） */
.book-sec-page .blk-steps li { margin: 12px 0; padding: 16px 20px 16px 58px; background: var(--card); border: 1px solid var(--rule); border-radius: 2px; color: var(--ink); font-size: 17px; scroll-margin-top: 84px; }
.book-sec-page .blk-steps li::before { top: 15px; left: 14px; width: 30px; height: 30px; font-size: 15px; line-height: 30px; color: var(--color-on-primary); background: var(--brick); border-radius: 2px; }
.bgroup > .bpara { margin-left: 58px; padding-left: 16px; border-left: 2px solid var(--rule-soft); font-size: 15px; color: var(--ink3); }
.bgroup > details.bnote { margin-left: 58px; }
/* 步骤号用教材原书编号（data-n），跨分组连续；不用 CSS counter（每 ol 会重置成 1231） */
.book-sec-page .blk-steps { counter-reset: none; }
.book-sec-page .blk-steps li { counter-increment: none; }
.book-sec-page .blk-steps li::before { content: attr(data-n); }

/* === 悬浮快捷导航（宽屏固定右侧，booknav.js scrollspy） === */
.book-nav { position: fixed; top: 96px; right: 18px; z-index: 90; display: none; width: 190px; max-height: calc(100vh - 140px); overflow: auto; padding: 12px 14px; background: var(--card); border: 1px solid var(--rule); border-radius: 2px; box-shadow: var(--shadow-2); }
@media (min-width: 1420px) { .book-nav { display: block; } }
.bn-head { margin: 0 0 8px; font-family: var(--mono); font-size: 10.5px; letter-spacing: 2px; text-transform: uppercase; color: var(--ink3); }
.bn-item { display: flex; align-items: baseline; gap: 8px; padding: 5px 0; border-top: 1px solid var(--rule-soft); color: var(--ink2); font-size: 12.5px; line-height: 1.45; }
.bn-item:hover { color: var(--brick); text-decoration: none; }
.bn-n { flex-shrink: 0; min-width: 20px; font-family: var(--mono); font-size: 11px; color: var(--brick); }
.bn-t { display: -webkit-box; overflow: hidden; -webkit-line-clamp: 2; -webkit-box-orient: vertical; }
.bn-item.active { color: var(--ink); font-weight: 600; }
.bn-top { margin-top: 8px; border-top: 1px solid var(--rule); }

/* 任务头：卡内多功能段切分（步骤号重启 = 新任务，meta.tasks 提供双语名） */
.btask-h { display: flex; align-items: baseline; gap: 12px; margin: 34px 0 4px; padding-top: 16px; border-top: 1px solid var(--rule); }
.btask-no { font-family: var(--mono); font-size: 15px; color: var(--brick); }
.btask-t { font-size: 18px; font-weight: 700; letter-spacing: .5px; }
.btask-label { margin-left: auto; font-family: var(--mono); font-size: 10px; letter-spacing: 2.5px; color: var(--ink3); }

/* === TASK 子页：任务入口链接 + 子页排版 === */
.task-links { display: flex; flex-direction: column; }
.task-link { display: flex; align-items: baseline; gap: 14px; padding: 18px 4px; border-bottom: 1px solid var(--rule-soft); }
.task-link:hover { background: var(--brick-tint); text-decoration: none; }
.task-no { flex-shrink: 0; font-family: var(--mono); font-size: 13px; letter-spacing: 1px; color: var(--brick); }
.task-t { flex: 1; font-size: 17.5px; font-weight: 600; color: var(--ink); }
.task-link:hover .task-t { color: var(--brick); }
.task-arrow { color: var(--brick); flex-shrink: 0; }
.task-kicker { margin: 0 0 6px; font-family: var(--mono); font-size: 12px; letter-spacing: 2.5px; color: var(--brick); }
.breadcrumb .bc-sep { margin: 0 8px; }
.book-task-page .card-nav { margin-top: 44px; }
.book-task-page .bgroup:first-child { margin-top: 8px; }

/* 概念区：从正文单拎的名词解释（meta.concepts） */
.bsec-concepts { margin: 26px 0 30px; padding: 20px 26px; background: var(--card); border: 1px solid var(--rule); border-left: 3px solid var(--brick); border-radius: 2px; }
.bsec-concepts h2 { display: flex; align-items: baseline; gap: 12px; margin: 0 0 14px; font-size: 15px; letter-spacing: 3px; color: var(--brick); }
.bconcept { margin: 0 0 14px; }
.bconcept:last-child { margin-bottom: 0; }
.bc-term { display: block; margin-bottom: 5px; font-size: 16px; font-weight: 700; color: var(--brick-deep); }
.bc-term a { text-decoration: underline; text-underline-offset: 3px; text-decoration-thickness: 1px; }
.bc-def { margin: 0; color: var(--ink2); font-size: 14.5px; line-height: 1.75; }

/* NOTE/TIP：默认折叠，点击展开 */
details.bnote { max-width: 72ch; margin: 14px 0; border: 1px solid var(--rule); border-left: 3px solid var(--hue-amber); border-radius: 2px; background: var(--card); }
details.bnote.tip { border-left-color: var(--hue-green); }
details.bnote summary { display: flex; align-items: center; gap: 10px; padding: 9px 14px; cursor: pointer; list-style: none; font-size: 13.5px; }
details.bnote summary::-webkit-details-marker { display: none; }
.bnote-tag { font-family: var(--mono); font-size: 10.5px; letter-spacing: 1.5px; color: var(--brick); white-space: nowrap; }
details.bnote.tip .bnote-tag { color: var(--hue-green); }
.bnote-sum { color: var(--ink3); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; flex: 1; }
.bnote-go { font-family: var(--mono); font-size: 10.5px; color: var(--ink3); }
details.bnote[open] .bnote-go::after { content: "−"; }
details.bnote:not([open]) .bnote-go::after { content: "+"; }
details.bnote[open] summary { border-bottom: 1px solid var(--rule-soft); }
details.bnote p { margin: 0; padding: 12px 14px; font-size: 14.5px; line-height: 1.8; color: var(--ink2); }

/* 图片：单图全宽、连图网格、页码角标、:target 灯箱 */
.fig-one, .fig-run { margin: 6px 0 18px; }
.fig-run { display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: 12px; }
/* 单图不强行拉满栏宽：按原图尺寸显示，超宽才收缩，超高限 78vh（竖长 UI 截图不会撑成巨人）；不足栏宽时居中 */
.fig-one .bfig { text-align: center; }
.fig-one .bfig-img { display: inline-block; max-width: 100%; }
.fig-one .bfig img { width: auto; max-width: 100%; max-height: 78vh; }
.bfig { position: relative; margin: 0; }
.bfig-img { display: block; border: 1px solid var(--rule); border-radius: 2px; overflow: hidden; background: #fff; }
.bfig img { width: 100%; height: auto; display: block; background: var(--img-bg); min-height: 60px; }
.bfig figcaption { padding: 5px 2px 0; font-family: var(--mono); font-size: 11.5px; letter-spacing: 1px; color: var(--ink3); }
.bfig-close { visibility: hidden; color: var(--brick); text-decoration: underline; }
.bfig:target { position: fixed; inset: 0; z-index: 400; display: flex; flex-direction: column; align-items: center; justify-content: center; background: rgba(31, 42, 61, .94); padding: 24px; margin: 0; }
.bfig:target .bfig-img { border: none; max-width: 96vw; max-height: 88vh; overflow: visible; }
.bfig:target img { max-width: 96vw; max-height: 88vh; width: auto; height: auto; }
.bfig:target figcaption { color: #faf7f0; padding-top: 12px; }
.bfig:target .bfig-close { visibility: visible; }

/* 课目录页 / review 页 */
.tag.quiz-tag { color: var(--brick); border-color: var(--brick-rule); font-family: var(--mono); letter-spacing: 1px; }
.book-hero .intro { max-width: 640px; }
.tag.book-link { color: var(--brick); border: 1px solid var(--brick-rule); }
.tag.book-link:hover { background: var(--brick-tint); }
.book-drp { margin: 0 0 8px; max-width: 760px; }
@media (max-width: 640px) {
  .bsc-title { font-size: 25px; }
  .fig-run { grid-template-columns: 1fr; }
  .bnote-sum { max-width: 46vw; }
  .bgroup > .bpara, .bgroup > details.bnote { margin-left: 0; }
  .bgroup > .bpara { padding-left: 0; border-left: none; }
}

/* === 动效降级 === */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
}

/* === 手机适配：640px 以下纵向堆叠 === */
@media (max-width: 640px) {
  .site-nav { gap: 3px 10px; padding: 5px 14px; min-height: 0; }
  .logo-text { font-size: 15px; }
  .nav-tools { width: 100%; justify-content: flex-end; gap: 6px; }
  #search-box { width: 120px; padding: 5px 9px; font-size: 12px; }
  .nav-tools button { padding: 4px 7px; }
  #search-results { width: min(320px, 90vw); }
  .hero { padding: 56px 0 40px; }
  .hero h1 { font-size: 34px; }
  .axis-row { gap: 16px; padding: 22px 4px; }
  .axis-title { font-size: 19px; }
  .sec-head h2 { font-size: 23px; }
  .topic-grid { grid-template-columns: 1fr; }
  .page-hero { padding: 44px 0 32px; }
  .page-hero h1 { font-size: 30px; }
  .card-hero h1 { font-size: 32px; }
  .card-hero .meta { gap: 8px 20px; }
  .card-page section.sec-block { padding: 40px 0; }
  .card-page section h2 { gap: 12px; }
  .sec-num { font-size: 24px; }
  .sec-title { font-size: 21px; }
  .sec-sub { letter-spacing: 2px; }
}

/* === L4 调色交互演示（color-demo.js 渲染） === */
.color-demo { margin: 20px 0; padding: 24px; background: var(--card); border: 1px solid var(--rule); border-radius: 2px; }
.cd-stage { text-align: center; }
.cd-stage canvas { width: 100%; max-width: 480px; height: auto; border: 1px solid var(--rule); border-radius: 2px; }
.cd-sliders { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; margin-top: 16px; }
.cd-label-row { display: flex; align-items: center; justify-content: space-between; gap: 8px; margin-bottom: 4px; }
.cd-label-row label { font-size: 13px; font-weight: 600; }
.cd-badge { min-width: 4ch; padding: 1px 8px; text-align: center; font-family: var(--mono); font-size: 12px; background: var(--brick-tint); color: var(--brick-deep); border: 1px solid var(--brick-rule); border-radius: 2px; }
.cd-slider input[type="range"] { width: 100%; accent-color: var(--brick); }
.color-demo.cd-motion .cd-badge { transition: background .15s; }
.cd-footer { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 12px; margin-top: 16px; }
.cd-hint { margin: 0; color: var(--ink3); font-size: 13px; }
.cd-reset { padding: 7px 16px; border: 1px solid var(--brick); border-radius: 2px; background: transparent; color: var(--brick); font-weight: 600; cursor: pointer; transition: background .15s; }
.cd-reset:hover { background: var(--brick-tint); }
@media (max-width: 640px) {
  .cd-sliders { grid-template-columns: 1fr; }
}

/* === 学习进度：标记按钮 / 进度条 / 已学条目 === */
.learned-row { margin: 16px 0 0; }
.mark-btn { display: inline-flex; align-items: center; gap: 8px; padding: 7px 18px; border: 1px solid var(--brick-rule); border-radius: 2px; background: transparent; color: var(--brick); font-family: inherit; font-size: 13.5px; letter-spacing: .5px; cursor: pointer; transition: background .15s, color .15s, border-color .15s; }
.mark-btn:hover { background: var(--brick-tint); }
.mark-btn.done { background: var(--brick); border-color: var(--brick); color: var(--color-on-primary); }

.unit-progress { display: flex; align-items: center; gap: 12px; margin: 0 0 16px; font-family: var(--mono); font-size: 12.5px; color: var(--ink3); }
.up-bar { display: inline-block; width: 160px; height: 4px; background: var(--rule-soft); border-radius: 2px; overflow: hidden; vertical-align: middle; }
.up-bar i { display: block; height: 100%; background: var(--brick); border-radius: 2px; }
.up-num { letter-spacing: 1px; }

.card-list li.learned > a { color: var(--ink3); }
.card-list li.learned > a::after { content: " ✓"; color: var(--ok); font-weight: 700; text-decoration: none; }

/* === 卡片页底部翻页导航 === */
.card-nav { display: flex; gap: 12px; margin-top: 64px; }
/* 页首同款导航：紧挨面包屑，间距反过来 */
.card-nav.card-nav-top { margin-top: 14px; margin-bottom: 40px; }
.card-nav > a, .card-nav > span { flex: 1; display: flex; flex-direction: column; gap: 5px; padding: 13px 16px; border: 1px solid var(--rule-soft); border-radius: 2px; }
.card-nav > a:hover { border-color: var(--brick-rule); background: var(--brick-tint); text-decoration: none; }
.card-nav .cn-next { text-align: right; }
.card-nav .cn-empty { border-color: transparent; }
.cn-dir { font-family: var(--mono); font-size: 11px; letter-spacing: 2px; color: var(--ink3); }
.cn-title { font-size: 14.5px; font-weight: 600; line-height: 1.5; }
@media (max-width: 640px) {
  .card-nav { flex-direction: column; }
  .card-nav .cn-next { text-align: left; }
  .card-nav .cn-empty { display: none; }
  .up-bar { width: 120px; }
}

/* === 术语表（Glossary） === */
.terms-search { max-width: 480px; margin: 10px 0 4px; }
.terms-search input { width: 100%; padding: 10px 14px; border: 1px solid var(--rule); border-radius: 2px; font-size: 14px; background: transparent; color: var(--ink); }
.terms-search input:focus { outline: none; border-color: var(--brick); }
.terms-cat { margin: 30px 0; }
.terms-cat h2 { display: flex; align-items: baseline; gap: 10px; font-size: 15px; font-weight: 600; letter-spacing: .3px; color: var(--ink); border-bottom: 1px solid var(--rule); padding-bottom: 8px; margin-bottom: 14px; }
.terms-cat .sec-sub { font-family: var(--mono); font-size: 11px; letter-spacing: 1px; color: var(--ink3); }
.term-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 14px; }
.term-card { display: flex; flex-direction: column; gap: 6px; padding: 14px 16px; border: 1px solid var(--rule-soft); border-radius: 2px; transition: border-color .15s, background .15s; }
.term-card:hover { border-color: var(--brick-rule); background: var(--brick-tint); text-decoration: none; }
.term-name { font-family: var(--serif); font-size: 17px; font-weight: 700; letter-spacing: .3px; color: var(--ink); }
.term-card:hover .term-name { color: var(--brick); }
.term-def { font-size: 13px; line-height: 1.7; color: var(--ink3); }
.term-tags { display: flex; flex-wrap: wrap; gap: 4px; margin-top: 2px; }
.term-tags span { font-size: 11px; line-height: 1.4; color: var(--ink3); border: 1px solid var(--rule-soft); padding: 1px 7px; border-radius: 2px; }
.term-card:hover .term-tags span { color: var(--ink2); border-color: var(--brick-rule); }
.term-page .term-title { font-family: var(--serif); font-size: 30px; font-weight: 700; letter-spacing: .5px; color: var(--ink); margin: 8px 0 4px; }
.term-links { margin: 30px 0 0; border-top: 1px solid var(--rule); padding-top: 16px; }
.term-links h2 { font-size: 13px; font-weight: 600; letter-spacing: .3px; color: var(--ink2); margin-bottom: 12px; }
.term-links .tag-row { display: flex; flex-wrap: wrap; gap: 8px; }
@media (max-width: 640px) {
  .term-grid { grid-template-columns: 1fr; }
}

/* === 阅读标尺：跟随鼠标的横向聚焦带（带外轻压暗，带内通透；上下砖红发丝线定位） === */
:root { --ruler-dim: rgba(31, 42, 61, .05); }
html[data-theme="dark"] { --ruler-dim: rgba(0, 0, 0, .28); }
.ruler-band { position: fixed; top: 0; left: 0; right: 0; z-index: 250; height: 76px; pointer-events: none;
  border-top: 1px solid var(--brick-rule); border-bottom: 1px solid var(--brick-rule);
  box-shadow: 0 0 0 100vmax var(--ruler-dim);
  transition: transform .07s ease-out; }
#ruler-toggle[aria-pressed="true"] { color: var(--brick); border-color: var(--brick); }

/* === 步骤勾选：每步右侧圆形勾选钮；完成 = 砖红实心打勾 + 整步变淡；悬浮导航同步划线 + 计数 === */
.book-sec-page .blk-steps li { padding-right: 54px; transition: border-color .15s, opacity .2s; }
.book-sec-page .blk-steps li:hover { border-color: var(--brick-rule); }
.step-check { position: absolute; top: 16px; right: 14px; width: 26px; height: 26px; padding: 0;
  border: 1px solid var(--rule-strong); border-radius: 50%; background: transparent; cursor: pointer;
  transition: border-color .15s, background .15s, transform .15s; }
.step-check:hover { border-color: var(--brick); transform: scale(1.12); }
.step-check::after { content: "✓"; position: absolute; inset: 0; display: flex; align-items: center; justify-content: center;
  font-size: 14px; line-height: 1; color: var(--color-on-primary); opacity: 0; }
.book-sec-page .blk-steps li.step-done { opacity: .45; }
.book-sec-page .blk-steps li.step-done:hover { opacity: .7; }
li.step-done .step-check { background: var(--brick); border-color: var(--brick); }
li.step-done .step-check::after { opacity: 1; }
.bn-item.bn-done { opacity: .45; }
.bn-item.bn-done .bn-t { text-decoration: line-through; }
.bn-head { display: flex; align-items: baseline; justify-content: space-between; }
.bn-count { font-family: var(--mono); font-size: 13px; font-weight: 700; letter-spacing: 1px; color: var(--brick); }
.bn-prog { height: 4px; margin: 2px 0 12px; background: var(--rule-soft); border-radius: 2px; overflow: hidden; }
.bn-prog i { display: block; height: 100%; width: 0; background: var(--brick); transition: width .3s ease-out; }

/* === 悬停微交互：卡片浮起 + 箭头位移 + 按钮按压（只动 transform/opacity，降级由全局 reduce 块兜住） === */
.topic-card { transition: border-color .15s, background .15s, transform .18s ease-out, box-shadow .18s ease-out; }
.topic-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-2); }
.card-nav > a { transition: border-color .15s, background .15s, transform .18s ease-out, box-shadow .18s ease-out; }
.card-nav > a:hover { transform: translateY(-2px); box-shadow: var(--shadow-1); }
.axis-go, .more, .task-arrow { transition: transform .18s ease-out; }
.task-link:hover .task-arrow { transform: translateX(4px); }
#keys-toggle, #lang-toggle, #theme-toggle, #ruler-toggle { transition: color .15s, border-color .15s, transform .12s ease-out; }
#keys-toggle:active, #lang-toggle:active, #theme-toggle:active, #ruler-toggle:active { transform: scale(.9); }
#keys-toggle, #lang-toggle, #theme-toggle, #ruler-toggle { min-width: 44px; padding: 6px 10px; border: 1px solid var(--rule-strong); border-radius: 2px; background: transparent; color: var(--ink3); font-family: var(--serif); font-size: 13px; letter-spacing: 1px; cursor: pointer; }
#keys-toggle:hover, #lang-toggle:hover, #theme-toggle:hover, #ruler-toggle:hover { color: var(--brick); border-color: var(--brick); }
#keys-toggle[aria-expanded="true"] { color: var(--brick); border-color: var(--brick); }

/* === 术语悬停预览卡 === */
.term-pop { position: fixed; z-index: 300; max-width: 300px; padding: 14px 16px 10px;
  background: var(--popover); border: 1px solid var(--rule); border-top: 2px solid var(--brick);
  border-radius: 2px; box-shadow: var(--shadow-3); }
.term-pop .tp-title { margin: 0 0 4px; font-size: 15px; font-weight: 700; color: var(--ink); }
.term-pop .tp-en { font-family: var(--mono); font-size: 11px; font-weight: 400; letter-spacing: .5px; color: var(--ink3); }
.term-pop .tp-def { margin: 0; font-size: 13.5px; line-height: 1.7; color: var(--ink2); }
.term-pop .tp-go { margin: 8px 0 0; font-family: var(--mono); font-size: 10.5px; letter-spacing: 1px; color: var(--brick); }

/* === 步骤键盘流（J/L 移动、K 勾选）的聚焦态 === */
.book-sec-page .blk-steps li.step-focus { border-color: var(--brick); box-shadow: 0 0 0 3px var(--brick-tint); }

/* === 快捷键练习：点击「按给我看」后听键盘，按对打勾 === */
.key-trainer { display: flex; align-items: center; gap: 14px; margin: 12px 0; padding: 14px 18px;
  background: var(--card); border: 1px solid var(--rule); border-radius: 2px; }
.key-trainer .kt-keys { display: flex; gap: 5px; flex-shrink: 0; }
.key-trainer kbd { padding: 4px 9px; font-family: var(--mono); font-size: 13px;
  background: var(--ink); color: var(--paper); border-radius: 4px; box-shadow: 0 2px 0 rgba(31,42,61,.35); }
html[data-theme="dark"] .key-trainer kbd { background: #0d0a12; box-shadow: 0 2px 0 rgba(0,0,0,.5); }
.key-trainer .kt-label { flex: 1; font-size: 14.5px; color: var(--ink2); }
.key-trainer .kt-btn { flex-shrink: 0; padding: 5px 14px; font-family: var(--mono); font-size: 12px; letter-spacing: 1px;
  border: 1px solid var(--rule-strong); border-radius: 2px; background: transparent; color: var(--ink3); cursor: pointer; }
.key-trainer .kt-btn:hover { color: var(--brick); border-color: var(--brick); }
.key-trainer.armed { border-color: var(--brick); box-shadow: 0 0 0 3px var(--brick-tint); }
.key-trainer.armed .kt-btn { color: var(--brick); border-color: var(--brick); }
.key-trainer.passed { border-color: var(--hue-green-rule); }
.key-trainer.passed .kt-btn { color: var(--ok); border-color: var(--hue-green-rule); }
/* 键帽先藏后揭晓：答对（passed）才显示正确键位，之前只显示 ? 占位 */
.key-trainer .kt-keys { visibility: hidden; }
.key-trainer.passed .kt-keys { visibility: visible; }
.key-trainer.passed .kt-mystery { display: none; }
.key-trainer .kt-mystery { display: flex; flex-shrink: 0; }
.key-trainer .kt-mystery kbd { padding: 4px 9px; font-family: var(--mono); font-size: 13px;
  background: transparent; color: var(--ink3); border: 1px dashed var(--rule-strong); border-radius: 4px; }

/* === 综合自测：题目出处标签 + 错题复盘 === */
.quiz-src { margin-left: 10px; padding: 1px 8px; border: 1px solid var(--rule); border-radius: 2px;
  font-family: var(--mono); font-size: 10.5px; letter-spacing: .5px; color: var(--ink3); }
.quiz-pool-sec { margin-top: 36px; padding-top: 0; border-top: none; }
.quiz-wrongs { margin-top: 28px; }
.quiz-wrongs > h3 { margin: 0 0 14px; font-size: 17px; font-weight: 700; color: var(--ink); }
.quiz-wrong { margin: 12px 0; padding: 16px 20px; background: var(--card);
  border: 1px solid var(--rule); border-left: 3px solid var(--bad); border-radius: 2px; }
.quiz-wrong ul { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 6px; }
.quiz-wrong li { padding: 7px 14px; border: 1px solid var(--rule); border-radius: 2px;
  font-size: 13.5px; color: var(--ink2); }
.quiz-wrong li.right { border-color: var(--ok); background: rgba(61, 122, 78, .08); color: var(--ok); font-weight: 600; }
.quiz-wrong li.wrong { border-color: var(--bad); background: rgba(176, 58, 46, .07); color: var(--bad); }

/* === flashcard 自评（认识/不认识） === */
.fc-assess { position: absolute; left: 0; right: 0; bottom: 12px; display: flex; justify-content: center; gap: 10px; z-index: 2; }
.fc-assess button { padding: 4px 14px; font-size: 12px; font-family: var(--mono); letter-spacing: 1px;
  border: 1px solid var(--rule-strong); border-radius: 2px; background: var(--card); color: var(--ink3); cursor: pointer; }
.fc-assess button:hover { color: var(--brick); border-color: var(--brick); }
.blk-flashcard.fc-known .fc-inner { outline: 2px solid var(--hue-green-rule); outline-offset: 2px; }
.blk-flashcard.fc-unknown .fc-inner { outline: 2px solid var(--bad); outline-offset: 2px; }

/* === compare 滑块：图片上直接拖拽时的手感 === */
.blk-compare { touch-action: pan-y; }
.blk-compare.dragging { cursor: ew-resize; }

/* === 快捷键小抄面板（⌨ 按钮 / ? 键） === */
.keys-pop { position: fixed; inset: 0; z-index: 400; display: flex; align-items: center; justify-content: center; }
.keys-pop[hidden] { display: none; }
.kp-backdrop { position: absolute; inset: 0; background: rgba(28, 20, 16, .38); backdrop-filter: blur(2px); }
html[data-theme="dark"] .kp-backdrop { background: rgba(5, 3, 10, .55); }
.kp-panel { position: relative; width: min(700px, calc(100vw - 48px)); max-height: min(82vh, 660px); overflow: auto;
  padding: 26px 30px 16px; background: var(--popover); border: 1px solid var(--rule);
  border-top: 2px solid var(--brick); border-radius: 8px; box-shadow: var(--shadow-3); }
.kp-panel.kp-in { animation: kp-in .18s ease-out; }
@keyframes kp-in { from { opacity: 0; transform: translateY(10px) scale(.97); } }
.kp-close { position: absolute; top: 10px; right: 12px; padding: 2px 10px; font-size: 18px; line-height: 1.4;
  border: 1px solid var(--rule-strong); border-radius: 2px; background: transparent; color: var(--ink3); cursor: pointer; }
.kp-close:hover { color: var(--brick); border-color: var(--brick); }
.kp-title { margin: 0 0 14px; font-size: 17px; font-weight: 700; color: var(--ink); }
.kp-cols { display: grid; grid-template-columns: 1fr 1fr; gap: 8px 28px; }
@media (max-width: 620px) { .kp-cols { grid-template-columns: 1fr; } }
.kp-cols h4 { margin: 6px 0 4px; font-family: var(--mono); font-size: 11px; font-weight: 400;
  letter-spacing: 1.5px; text-transform: uppercase; color: var(--ink3); }
.kp-list { margin: 0; padding: 0; list-style: none; }
.kp-row { display: flex; align-items: center; gap: 10px; padding: 5px 0; }
.kp-keys { display: flex; gap: 4px; flex-shrink: 0; min-width: 92px; justify-content: flex-end; }
.kp-keys kbd { padding: 3px 8px; font-family: var(--mono); font-size: 12px;
  background: var(--ink); color: var(--paper); border-radius: 5px; box-shadow: 0 2px 0 rgba(31,42,61,.35); }
html[data-theme="dark"] .kp-keys kbd { background: #0d0a12; color: var(--ink); box-shadow: 0 2px 0 rgba(0,0,0,.5); }
.kp-keys kbd:hover { transform: translateY(1px); box-shadow: 0 1px 0 rgba(31,42,61,.35); }
.kp-label { font-size: 13.5px; color: var(--ink2); }
.kp-foot { margin: 14px 0 0; padding-top: 10px; border-top: 1px dashed var(--rule);
  font-size: 12.5px; color: var(--ink3); }

/* === 新手指引巡游（tour.js，仅首页加载）：聚光挖洞 + 气泡卡 === */
#tour-root { position: fixed; inset: 0; z-index: 500; pointer-events: none; visibility: hidden; }
#tour-root.on { visibility: visible; }
.tour-hole { position: fixed; border-radius: 8px; pointer-events: auto;
  box-shadow: 0 0 0 9999px rgba(28, 20, 16, .55);
  outline: 1.5px solid var(--brick); outline-offset: 3px;
  transition: left .3s ease, top .3s ease, width .3s ease, height .3s ease; }
#tour-root.tour-snap .tour-hole, #tour-root.tour-snap .tour-card { transition: none; }
html[data-theme="dark"] .tour-hole { box-shadow: 0 0 0 9999px rgba(3, 2, 8, .72); }
.tour-card { position: fixed; pointer-events: auto; padding: 20px 22px 16px;
  background: var(--popover); border: 1px solid var(--rule); border-top: 2px solid var(--brick);
  border-radius: 8px; box-shadow: var(--shadow-3);
  transition: left .3s ease, top .3s ease; }
#tour-root.on .tour-card { animation: kp-in .18s ease-out; }
.tour-stepno { margin: 0 0 6px; font-family: var(--mono); font-size: 11px; letter-spacing: 2px; color: var(--brick); }
.tour-title { margin: 0 0 8px; font-size: 19px; font-weight: 700; color: var(--ink); }
.tour-body { margin: 0 0 14px; font-size: 14.5px; line-height: 1.75; color: var(--ink2); }
.tour-controls { display: flex; align-items: center; gap: 8px; }
.tour-spacer { flex: 1; }
.tour-skip { border: 0; background: none; padding: 6px 4px; font-size: 13px; color: var(--ink3); cursor: pointer; }
.tour-skip:hover { color: var(--brick); }
.tour-prev, .tour-next { padding: 7px 16px; font-size: 13.5px; border-radius: 2px; cursor: pointer;
  border: 1px solid var(--rule-strong); background: transparent; color: var(--ink2); }
.tour-prev:hover:not(:disabled) { color: var(--brick); border-color: var(--brick); }
.tour-prev:disabled { opacity: .35; cursor: default; }
.tour-next { background: var(--brick); border-color: var(--brick); color: var(--color-on-primary); font-weight: 600; }
.tour-next:hover { filter: brightness(1.08); }
@media (prefers-reduced-motion: reduce) {
  .tour-hole, .tour-card { transition: none; }
  #tour-root.on .tour-card { animation: none; }
}